Many in the industry have watched with interest (and perhaps a bit of schadenfreude) as Facebook shares have plunged to under $27. Obviously, multiple factors have contributed to some of the luster coming off this once glistening object, but a significant factor has to be concerns over Facebook’s ability to monetize its growing mobile user-base through advertising. But here’s the thing, digital publishers: mobile monetization isn’t just Facebook’s problem; it’s your problem too.

If anything, the publicity around Facebook’s mobile challenges brings to light what has become a very open secret among digital publishers – mobile isn’t a great advertising business. And it won’t be any time soon, either.

Rapidly changing consumer behavior has turned mobile into a massive media platform, with over 1/3 of US online adults owning 3 or more connected devices (typically a PC, smartphone, and tablet), going online multiple times a day, and from multiple locations – a segment Forrester calls the Always Addressable Customer. This is a tremendous opportunity from a content perspective – publishers can now engage audiences essentially whenever and wherever they are by building mobile apps galore and optimizing their websites for easy, on-the-go mobile and tablet consumption. But monetizing those content assets is another story altogether.

Sure, US mobile display ad spending will eclipse a billion dollars this year and network players like Millennial and Google will continue to reap the rewards. Meanwhile, traditional content creators will struggle to find and deliver scale – a complaint we often hear from media buyers eager to engage mobile audiences. If this sounds like a repeat of the history of digital advertising, it’s because fragmentation and lack of scale is true for almost every media innovation.

But here’s the rub: display ad spending is becoming a rather large pie (over $27 billion in 2016, according to our most recent projections), with many factors pointing to premium publishers grabbing a larger share of it. However, by 2016, mobile display spending is unlikely to be a seventh of that, even as the big ad tech companies and mobile-focused startups solve for fundamental challenges like basic measurement and targeting. So even as mobile breaks out of infancy and into adolescence, its monetization prospects remain relatively meek and unlikely to reduce that elusive time-spent vs. media spend divide.

Some of the challenges plaguing the mobile media buying ecosystem will dissipate over the next few years. New creative tools will help ease the costs and pains of formatting for multiple screen formats and platforms. New tracking and audience identification methodologies will help ease some of today’s targeting limitations. But still, mobile advertising fundamentals will limit the market opportunity for the market to grow and publishers to monetize.

Most notably, measurement challenges will continue to cripple the mobile ad market. Whether we like it or not, most media formats earn their stripes fueling the DR engine. The rise of ecommerce in particular has been critical in the development of the online display and has laid the foundation for an emerging branding channel. Mobile ecommerce is clearly on the rise, but without a broadly accepted buying metric (like the click or the GRP), demand will remain limited. Moreover, attribution challenges – already a hot button in online advertising – become even more complex as mobile marketing campaigns attempt to drive in-store transactions through tools like location-based targeting.

All in all, this creates an incredibly challenging monetization environment for publishers. The good news is that mobile is unlikely to be profoundly disruptive for most digital publishers. While publishers in certain categories like social networking and weather are quickly becoming “mobile-first” publishers, our consumer suggests that most types of smart-phone media consumption is largely additive, not cannibalistic (like, for instance, the switch from newspapers to online news).

Nonetheless, supporting mobile content isn’t cheap, and publishers must still work to capture as many advertising dollars as possible – however limited. So what will successful publishers do? First, they’ll make it easy for buyers by finding ways to scale. Many publishers are shooting themselves in the foot by building mobile experiences – especially mobile apps – on a wide array of platforms. While editorial and content teams may love this flexibility, it absolutely destroys any ability of the publisher to deliver efficient scale to advertisers. Second, we expect automation to rapidly become the norm in mobile media buying and selling. Smart buyers and sellers will move quickly to eliminate as many transaction costs as possible – whether through RTB-enabled buys or some other programmatic method – in order to reallocate resources to higher-value activities. To this end, it wouldn’t surprise me to see some publishers experiment with RTB-only mobile ad sales.

But these are only half-measures (albeit ones in the publisher’s control). For mobile advertising to truly reach its potential, advertisers, publishers, and tech vendors will have to work together to totally reinvent the medium. Today’s facsimile of PC-based advertising experiences just won’t do in a medium where limited scale, fragmentation, and demands for unwavering ad relevance are the norm.